Hæmocytometer.



, W. Tf KENNEDY.

H/EMOCYTOMETER. APPLICATION FILED EEB.8.1915.

l, 182,384. Patented May'9, 1916.

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WILLIAM THOMSON KENNEDY, 0F TORONTO, ONTARIO, CANADA.

y HEMOCYTOMETER.

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Specification of Letters Patent.

Patented May 9, 1916.

Application filed February 8, 1915. Serial No. 6,833.

To all whom 'it may concern Be it known that LVILLIAM THOMSON KENNEDY, a subject of the King of Great Britain, and resident of the city of To ronto, county of York, Province of Ontario, in the Dominion of Canada, have invented certain new and useful Improvements in Haemocytometers, described in the following speciiication and illustrated in the accompanying drawings, that yform part of the same. f The principal objects of the invention are to facilitate the counting` of red and white corpuscles in the blood and cerebro-spinal fluid and bacteria, providing a scale adapted for use in the eye-piece of the microscope thereby eliminating the difficulties met with iii the use of ruled counting chambers in which the ruled lines form ditches or grooves in which the corpuscles concentrate.

A further object is to provide a scale which is arranged in decimal factors and which is adapted for use with various 0b.- jectives and different ranges of microscopes.

The principal feature of the invention consists in the novel arrangement of a scale in circle formation divided into segments wherein the areas of various divisions are factors of other divisions to allow of universal use.

In the drawings, Figure l is a longitudinal sectional view of a microscope eye-piece showing the locationof the scaled member. Fig. 2 is an enlarged diagram of the scale. Fig.y 3 is an enlarged diagram of the scale showing certain defined corresponding areas. Fig. t is an enlarged diagram of the scale showing a special large area defined. Fig. 5 is an enlarged diagram of the scales showinganother special area defined. Fig. 6 is anenlarged diagram of the adjusting scale arranged upon the counting chamber.

In reference to the drawings A is a central circular area which when objective 6 or l/G is used, incloses l/500th of a square millimeter of counting chamber. Outside of the area A is a circle inclosingan area B which when objective 3 or l/3 is used is to the central area A and are numberedV l to 0.

WV is a circle surrounding the circle V and inclosing a total area D which when Yobjective 3 or l/S is used for counting cor- Apuscles in cerebro-spinal Huid incloses l squaremillimeter of counting chamber.

X is a circle surrounding the circle 1W and inclosing therebetween an annular space which is divided by radial lines into 10 equal spaces B1 which are numbered l to Oeach of which are equal in area to the Y is an outer circle surrounding the circle X and inclosing a total area E which when objective 6 or l/G is used incloses an area of l/lO of a square millimeter.

i'lhe scale as thus described is inscribed into 2() equal` upon the glass disk l arranged intermediate f of the length ofthe eye-piece 2 and the inscribed surface is covered by a protecting glass disk 3 both of which are firmly, se-

cured in place.

yThe counting chamber in which Vthe fluid x is placed is provided with a scale of adjusting lines as illustrated in Fig. 6 with which the circle WV is focused. In this scale the spaces indicated are measured as follows: a:l.598 mm: 521.1283 mm: @2.5642 mm: 2.2382 mm: and 62.1802 mm.

The scales o; and are used in focusing for B areas when the focus of the microscope is adjusted till the diameter of the circle `W on the scale coincides with the distance a or b according to the objective used and the scales c, ci and c are used for A areas.

In counting red blood corpuscles, the

blood is diluted to 1 in 200 with normal saline and with objective 6 or 1/6 the areas A, A1, A2, etc., each give an area of 1/500 of a square mm. of counting surface, therefore, with 1 Factor 5-06 area.

fiiiution.

mm. thickness gives factor liooood Therefore, by multiplying the average of the number of corpuscles observed in the areas A, A1, etc., by 1,000,000 Will give the number of red corpiiscles per cubic millinieter. n Y

In counting White corpuscles, the blood is diluted to l in 10 with one per cent. acetic acid solution to Which has been added a fevv drops of saturated `methylene coloring to one ounce of the solution. Using objective 3 or 1/3 and areas B, B1, B2, etc., or With objective 6 Orl/6 and area E gives an area of l/10 square min. of area of counting chamber, therefore,

1 Factor square min. area.

l -Odilutioii.

1 1 1 0 mm. thickness gives factor mvpuscles, the corpuscles are stained by the use o-f methylene coloring Without dilution. Using objective 3 0r 1/3 and area D Will give l square mm. of counting chamber, therefore, Y

Factor 1 square nim. area.

1 dilution.

1 1 i6 mui. thickness gives factor Therefore, by multiplying the number of corpuscles observed in area D by 10 WillY give the number per cubic millimeter.

In counting bacteria, using objective 6 or 1/6 and area C gives 1/20,000 of a square mm. of area of counting chamber, or using i f objective 1/12 oil immersion and area A gives 1/2000 square mmLof-COUIlt/lg Chamber area.

- fectly smooth. Tliis'obviates the diihculties l inet With in the use of ruled counting chambersv Where the ruled lines form grooves which. concentrate the corpuscles or bacteria and render the counting diflicult. The difficulty of difference in focus ofthe lines and corpuscles is also obviated. The counting areas being arranged in the eye-piece and capable of use with different objectives eX- tends the use of the instrument and insures more accurate work and effects a consequent lessening of the strain upon the eyes. More areas can be obtained and coiisequentlya better average and greater accuracy can be had. A

What I claim as my invention is 1. A haemocytometer, comprising, a scale arranged in the eye-piece of the microscope and havingannular areas divided intov segmental decimal divisions. Y

2. A liaemocytometer, comprising, a scale adapted to be arranged in the eye-piece of the microscope having a plurality of concentriccircular areas and radial division lines dividing certain of the annular areasforined between the circular areas into decimal factors.

3. A haemocytometer, comprising, a scale adapted to be arranged in the eye-piece of the vmicroscope having -a central circular area and a concentric annular area surrounding the central area and` divided 'radially into decimal areas leach equal to the central area.

4. A haemocytoineter, comprising, a scale adapted to be arranged in the eye-piece of the microscope having a 'central inner circular area, a central larger area, an annular area encircling tlie central areas and forming a decimal multiple of the smaller area and divided radially into areas equal to said smaller area, and an annular area arranged outsidev the inner annular area forming a decimalv multiple of the larger Vcentral area and divided radially into Vareas equal to the larger central area.

5. A'haeniocytometer, comprising, Ya scale adapted to be arringed in the eye-piece of the microscope yhaving a centralV inner circulararea, a central larger area an annular W latter annular area and divided into ten areaseach equal to the area of the central inner area,` a central area including the aforesaid areas, and an annular area sur-V rounding this latter area divided radially into'ten areas each equalto the larger central area Within the first annular area.

6.7A liaemocyto-meter, comprising, a scale adapted to be arranged in the eye-piece 'of the microscopeV having a central circular area, an annular larea encircling Vsaid central area divided intoten equal segments, each of saidy segments having an area equal 1 to the central area, Ya focusing circle on 4said scale adapted to represent according to the objective used a diameter of .564-2 mm., .2382 nim. or .1802 mm. Y Y

7. A haemocytometer, comprising, ascale arranged in the eye-piece of the microscope rounding the central areas divided radially into ten areas each equal to the inner cen- 15 tral area, and an annular area divided into ten areas each equal to the larger central area.

Signed at the city of Toronto, county of York, Ontario, Canada,. this 1st day of 20 Feby. 1915.

WILLIAM THOMSON KENNEDY.

Witnesses:

E. HERON, H. A. TRIMBLE.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. C. 

